In one of those series of events that usually only happen in dreams—Jon Hamm (the enigmatic, chain-smoking star of “Mad Men”) drives around in a purple boot with a loquacious yellow mutt named Martha in tonight’s season premier of “Martha Speaks” on PBS.

Based on the best-selling books by Susan Meddaugh, “Martha Speaks” follows the adventures of a pup whose appetite for alphabet soup gives her the power of human speech. While the stories are geared for children ages 4 to 7, with the goal of increasing oral vocabulary, you don’t have to be a kid to appreciate the verbal richness of this spirited dog.

In tonight’s episode, Hamm plays an actor who is trying to save up enough money to create vocabulary calendars (watch the teaser below). He and Martha are joined in this adventure by Hamm’s real-life girlfriend, the actress Jennifer Westfeldt (“Friends with Kids”), and the couple’s German Shepherd mix, Cora. It’s a classic Martha plot with mistaken identity, verbal gaffes, silliness—plus a very animated Don Draper.